Improvement in rotary steam-engines



'Fl- LOMAS MCEWEN, OF CHICAGO, ILLINOIS-il',h f

` Lette/rsPatent No. 91,468, (lated June 15, 1869.

IMPROVEMENT IN RQTARY STEAM-ENGINES.

The Schedule referred to in these Letters Patent and making part of the same.

T 0 all whom @t mW!! fmcemi- On the periphery of the disk O is formed a radial Y Beit known that..I,.-T1 `10MAS McEwan, of Chicago, head or piston, b, which fills the chamber D at that in the county of .Gook, and Stateof Illinois, haveinpoint. i

vented certainnew and useful Improvementsin Rotary. Through the' top of the case A enters a dat cut-off f Steam-Engine; and I do hereby declare that the folor valve, E, asA clearly shown n iigs. 3 and 4, which is lowing is a full, clear, and exact description thereof, capable of being moved vertically, and of a width reference being had to -the accompanying drawings, greater than the diameter of chamber D, and rounded making part of this specification, and to the letters of on its lower end, so that, when this valve is pushed reference marked thereon, like letters indicating like into thecase, and bears against the edge of the disk t parts, wherever they occur. G, it will form a tight partition, or stop-head, across To enable others skilled in the art -to construct and Y the chamber D.

yuse my invention, I will' proceed to describe it. Y It is evident that if steam be forced into the cham- My Yinvention relatesY to'rotary steam-engines, and ber D, between the stop-head and the piston h, the consists principally in the arrangement of devices for latter will be forced around in the chamber, moving operating the valves.l Y Y with it the disk O, and revolving the shaft B and its l Figure 1 is a side elevation of my engine, with the connections. balance-wheel removed. When, however, the piston has travelled clear around Figure2, an 4elevationof the opposite side fromV the the chamber, it will come up on the opposite side of above. f f the stop-head from that on which steam is admitted, Figure 3, a vertical longitudinal section, on the line and, unless said head vis drawn out, would strike against aa-:c of fig. 4. it. To provide against this, there is connected with Figure 4is avertical cross-section through the centhe said head suitable arms and levers, operated by a tre, on the line y-y of iig. 1. cam on shaft B, which, when the piston has almost Figure .5, a modified form of the stop-head valve. reached the stop-head, draw said head back, and allow y Theengiue is of that class which consists of a c'ircuthe piston to pass under, after which the head is imlar body, or case, having mounted within it, on a shaft mediately brought back across the chamber, the steam ,passing through the centreot the case, a hub of less being cut oil' while the piston is passing under the Ldiameter' than the case itself, said hub being provided head. around or on its periphery withone or more radial On top of the case is an extension-chamber, closed heads or pistons, of such size and frm as vto lill the at the top, into which the stop-head passes when drawn space between the outer side ofthe hub and the outer up, the head having attached on top two stems t, which case, steam being admitted into the space behind the extend up through stuing-boxes, and are connected l said arms or pistons, betweenthem'. and valves which at their upper ends to a cross-head, L, as clearly shown enter through the case, and extend into and against'A in g. 4.. `the periphery of the hub, the said valves being drawn To one end of this cross-head Lis pivoted apendent out at regular intervals, to .allow-the piston-heads to pitman, K, jointed at its lower end to the long arm of pass. t au elbow-lever, J, which is pivoted on a stud, P, near In the drawing the cuter edge of the case, as shown in fig. 2. Arepresents the outer case, or body, formed in halves, The short arm of this lever J is connected with the and bolted together, and made witha flat base, so as reciprocating bar If, moved in one direction by the cam to be readily and lirmlyfastened in position. H, and brought back by the spring O.

Through the centre of this case, at right angles, One end of the bar I is formed into a rectangular passes a shaft, B, as shown in iigs. 3 and 4, the `case frame, which surrounds the shaft B, as shown in figs. having formed onk it, at the centre, hubs, or extensions, 2 and 4, thus supporting the bar, and guiding it in its `as shown in tig. 4, and being for therpurpose of lengthmovement. ening the distance between the points of bearing of On the outside of the bar, at its end, is a projecting the shaft, and thus giving it firmer support. portion, d, and on the shaft B is a cam, H, which is so Upon this shaft B, inside the case, is secured the located, that when the piston b, in its revolution, has circular head or vdisk C, ,concentric with the axi'sof nearly reached the stop-head E, said cam will strike, said shaft, and of less` diameter than the interior of projection'd, and force the bar I over and, through the the case A. p 4 medium of the lever J and pitman K, move the stop- From a point beginning at the periphery ofthe disk head up, and thus allow the piston to pass, by whichJ O, and extending outward, the case A is widened and time the cam will have passed the stud or projection,

. enlarged, so as to present, in cross-section, from said and the spring O will bring the parts back to their y point outward, a circular or tubular form on its inteoriginal positions. V p

rior, and the whole forming a circular tubular cham- The induction-port for the steam is shown at e, fig. ber or cylinder, D, around in the outer portion of the 3, being located as close as possible to the stop-head,

' case, and described from the axis of the shaft B as a and the eduction-port 'at f, close on the opposite side i centre. of the stop-head.

Over the induction-port e is placed a steam-chest, M, into which the steam is admitted through the pipe m, and within this chest is located a slide-valve, F, playing over the mouth of the port, and being operated by an eccentric, G, on the shaft B, which is connected with it by a. stem, o, playing through a stufliugbox on the under side of the chest, all as shown in figs. 1 and 4.

The purpose of this valve is to shut off t-he steam while the stop-head is raised, and until the piston passes by the port, and also for regulating the supply of steam when working expansively.

The exhaust-port is at all times open, there being no valves connected with it.

When the engine is to be operated, the shaft B is turned, so as to shut down the stop-head, and open the port e. Steam is then turned on, and, entering through said port, will force the head b around in the chamber D, until it reaches the exhaust-port j; when the valve F will cut o' the steam, and as soon as the piston passes the port j; the steam in the chamber D will escape through it, the stop-head rising at the same time, so that the piston may pass.

As soon as the piston has got past the stop-head it closes down, and, as soon as the piston is past the port e, the valve F opens, and steam is admitted, and so on successively.

On the shaft B, outside of the case, I secure any desired gearing or pulleys, from which to connect with the apparatus or machinery to he driven, the drawings showing a fly-wheel, P, on one end, and a pulley, B, on the other.

If desired, two or more stop-heads may be used, lo cated at different points around the case, or several piston-heads formed ou the disk C, thus having the force of the steam exerted to move the engine at all points in its revolution, and not requiring the pistons to be carried past the stop-heads by the momentum of the ily-wheel, as is the case where a single piston and stop-head are used.

This engine may be so built as to run in either direction at will, and, by adjusting the valve F and its connections, will work expansively.

Instead of the stop-head sliding, as described, it may be pivoted at one side, and swing or turn out into the extension-chamber, as shown in fig. 5.

It is obvious, that if desired, the chamber D may be of a. rectangular or elliptical form in its cross-section, the circular form being adopted only because of the ease of building and fitting the parts.

Having thus described my invention,

What I claim, is-

A rotary steam-engine, consisting of the case, with the chamber D, the disk c, with the piston or wing b, and the sliding-head E, operated by the elbow-lever J, yoke I, and cam H, all arranged substantially as described.

Witnesses: THOS. MOEW'EN.

WM. H. Lo'rz, A. Lnrsnee. 

